Device for punching metallic tubes



` (No Model.)

0. E.v OLMSTED.

DEVICE EOE P-NGEI'NG METALLIC TUBES. Y Y

No. 252,247. .E Patented Jan. 10,1882.

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UNITED STATES PATENT OFFICE.

OSGAR B. OLMSTED, Ole" BELOIT, WISCONSIN.

DEVICE Foa PUNCHING METALLIC TUBES.

SPECIFICATION forming part of Letters Patent' No. 252,247, dated January 10, '1882.

Application tiled July 7, 1881. (No model.)

To all whom it may'concern:

Be it known that I, Oso/IR B. OLMsTED, a

citizen ofthe United States, residing at Beloit,

' by use.

in the county of Rock and `State of Wisconsin, have invented certain new and useful Improvements in Mandrels andDiesforPunchingPipe, of which the following is a specification.

Myinvention relates toimprovementsin dies and mandrels for punching pipe, in which a die and mandrel are placed inside the pipein such a way as to ll the inside of the pipe directly under the punch while the hole is being punched; and the objects of myimproyements are to provide a die and mandrel that will lill the pipe "and prevent `the pipe from being crushed in while being punched, and that can be easily and cheaply `replaced when w'orn out I attain these objects by the mechanl ism illustrated in the accompanying drawing, which is a sectional view of the nimdrel, die, and'pipe.

Similar letters refer to similar parts.

The mandrel is in three parts, G B F. The

center piece, B, which should be made of steel,

is wedge-shaped at the end directly under the die D, and is provided with a slot-opening, E,

I totallow the metal cut away while punching to drop out. The lower piece, F, ofthe mandrel is convex on the under side, with its upperface flat and inclined to fit the lower face of the center piece, B. The top piece, G, is provided with a recess, H, for holding the die D in its proper place inside the pipe G under the punch The die D is convex on the upper side to lit the inside of the pipe to be punched, and is flat on its under side to tit the recess H. It is also provided with a hole through itvertically, i

directly under the punch7 to allow the metal cut out in punching to-pass through it and out at the slot in the Wedge B.

In working my invention the mandrel and die are placed in a suitable punchingmachine, and the wedge B is worked back and forth by any suitable mechanism, and the die and mandrel are alternately tightened in the pipe while the punch is being forced through it, and

loosened to allow the pipe to be moved lalong fori-another boleto-:be punched.

I am aware that prior to my invention, as

herein described, mandrels in three parts have OSCAR B. OLMSTED.

Witnesses:

J. B. Dow, T. P. GRAY. 

